Unitrunker Not quite there yet

[rocky28965]

I originally started a thread on this in the New Zealand discussion forums, but thought it may get more attention in here.

I have rewritten it as I have progressed somewhat.

I live in a semi-rural location with very little trunking coms & none listed on RadioReference.

I have searched both 400 & 800 MHZ for receivable control channels.
Came up with two only, both in the 400 MHz range.
One is MPT1327 protocol. Other is DMR protocol.
I've installed Unitrunker, DSDPlus & Virtual Cable.
I'm using 2 RTL2832U SDR's
Set them up in Unitrunker as signal & voice.
I have tried both the channels in unitrunker.
Both have strong signals & show 100% health.
Only the MPT1327 channel will open a viewing window.
There is no voice audio. Both SDR's show as running.
SDR1 with role of signal shows status of decoding.
SDR2 with role of voice shows status of parked.

I have since found, if I set audio & digital outputs to VB-Audio in the signal receiver, it will decode the DMR channel.
It’s most likely I have something set incorrectly.

I’ll try to attach some pics showing my settings, not sure how they will look.

 

[hrh17]

I'm guessing the DMR system you are receiving is vital you should use dsdplus fastlane +fmp24 for this, you'll need to map out the frequencies for dsdplus to monitor it.

For the MPT1327 system you'll also need to tell unitrunker what the frequencies are.

I'm based in NZ so flick me a PM happy to help.

 

[GTR8000]

Unitrunker does not decode DMR.

 

[sjacket99]

SDR Sharp with the DMR plugin will pick up DMR with 1 RTL. SDR Angel can receive DMR as well.

 

[rocky28965]

Gosh those pics came out better than I expected.
I see I had the wrong digital output selected on the VCO window of receiver scan.
I have changed it to VB-Audio but it made no difference to receiving MPT1327.
The correct control channel frequency is entered in park on the VCO window of the receiver signal.
This is how it is shown to do on all the tutorials I have seen.
The protocol is correct & it is showing 100% health.
So why is the receiver scan not getting any audio.
I have swapped the antennas on the SDR's but makes no difference.
I have also swapped the roles of the SDR';s but makes no difference.
The SDR's while both being RTL2832U are not identical & the one currently shown as signal has a 71.5 correction, while the other has none.

Regarding the DMR channel.
As I said in post #1
If I change the audio output to VB-Audio in the signal VCO & open DSD-Plus, it will decode the transmissions.

 

[GTR8000]

Regarding the DMR channel.
As I said in post #1
If I change the audio output to VB-Audio in the signal VCO & open DSD-Plus, it will decode the transmissions.

Right, because you're passing the digital modulation through to DSD+. That doesn't change the fact that Unitrunker doesn't decode DMR at all. Don't be fooled by the "DMR" display in the Protocol box, that was added just to aid in signal identification, nothing more.

Bottom line is that it's a waste of time running that DMR signal through Unitrunker. You'd be much better off doing it all natively in DSD+ using FMP24 as the tuner.

 

[rocky28965]

You are probably right, & I will look into that.

Would you happen to know why I am unable to receive the MPT1327 in Unitrunker ?

 

[hrh17]

you need to populate the frequencies so unitrunker knows what channel to go to for the voice receiver
LCN 105 - 415.3125
LCN 144 - 415.8000

 

[rocky28965]

Sounds like a solution, but where do I insert that ?

 

[rocky28965]

you need to populate the frequencies so unitrunker knows what channel to go to for the voice receiver
LCN 105 - 415.3125
LCN 144 - 415.8000

Could you explain how to do that please & how you got those two frequencies

 

[hrh17]

double click in the channels tab and type in the frequency needed.
LCN for MPT1327 is easy to figure out, the LCN matches the TD number from the mobile service bands pdf

https://www.rsm.govt.nz/assets/Uploads/documents/pibs/1356fceab7/mobile-service-bands-in-new-zealand-pib-23.pdf

D105# 415.31250
TD144# 415.80000

 

[rocky28965]

Thanks for pointing me in the right direction.
After putting those frequencies in I started receiving transmissions on those two.
Not much traffic here, but after a couple of hours three more LCN's appeared.
I'll attach the screen shot, showing them.
They would appear to be way out of the frequency range.

 

[rocky28965]

Anyone, I'm referring to the three LCN entries.
513
569
825

 

[hrh17]

I would say those are false positives from Unitrunker. Doesn't fit the band plan

 

[rocky28965]

Thanks